Per diem is a Latin term meaning "per day." It is commonly used in the context of work-related expenses, referring to the allowance given to cover daily expenses such as meals and transportation. However, there are several synonyms that can be used to describe the same concept, such as daily allowance, daily rate, daily stipend, daily wage, and daily subsistence. These synonyms are used interchangeably, depending on the context and industry they are being used in. For instance, in the travel industry, per diem is commonly used to refer to daily expenses while daily subsistence is commonly used in the military. Regardless of the term used, its purpose remains the same - to cover daily expenses in a particular field or career.